Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit aceecc06 authored by Junjie Wu's avatar Junjie Wu Committed by Stephen Boyd
Browse files

cpufreq: interactive: Delay evaluation of notification by 1ms 



Multiple migrations can happen together within short period if
scheduler is re-arranging a few tasks. In this case, it's only useful
to change frequency at the end of all migrations. Delay handling of
scheduler notification by 1ms.

Change-Id: I9ee7b1e93ce57c28919b5609c40dcde9bd14abed
Suggested-by: default avatarSaravana Kannan <skannan@codeaurora.org>
Signed-off-by: default avatarJunjie Wu <junjiew@codeaurora.org>
Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
parent 94137b29

Documentation/cpu-freq/governors.txt

+3 −3
Original line number Diff line number Diff line
@@ -312,9 +312,9 @@ information such as migration. If non-zero, this also implies governor 
sampling windows are aligned across CPUs, with same timer_rate,

regardless what align_windows is set to. Default is zero.



use_migration_notif: If non-zero, reevaluate CPU's frequency

immediately after receiving notification from scheduler. If zero,

ignore scheduler notification. Default is zero.

use_migration_notif: If non-zero, schedule hrtimer to fire in 1ms

to reevaluate frequency of notified CPU, unless the hrtimer is already

pending. If zero, ignore scheduler notification. Default is zero.



max_freq_hysteresis: Each time freq evaluation chooses policy->max,

next max_freq_hysteresis is considered as hysteresis period. During

drivers/cpufreq/cpufreq_interactive.c

+35 −12
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#include <linux/tick.h>

#include <linux/time.h>

#include <linux/timer.h>

#include <linux/hrtimer.h>

#include <linux/workqueue.h>

#include <linux/kthread.h>

#include <linux/slab.h>
@@ -37,6 +38,7 @@ 
struct cpufreq_interactive_policyinfo {

	struct timer_list policy_timer;

	struct timer_list policy_slack_timer;

	struct hrtimer notif_timer;

	spinlock_t load_lock; /* protects load tracking stat */

	u64 last_evaluated_jiffy;

	struct cpufreq_policy *policy;
@@ -52,6 +54,7 @@ struct cpufreq_interactive_policyinfo { 
	struct rw_semaphore enable_sem;

	bool reject_notification;

	bool notif_pending;

	unsigned long notif_cpu;

	int governor_enabled;

	struct cpufreq_interactive_tunables *cached_tunables;

	struct sched_load *sl;
@@ -775,33 +778,51 @@ static int load_change_callback(struct notifier_block *nb, unsigned long val, 
	struct cpufreq_interactive_tunables *tunables;

	unsigned long flags;



	if (speedchange_task == current)

		return 0;

	if (!ppol || ppol->reject_notification)

		return 0;



	if (!down_read_trylock(&ppol->enable_sem))

		return 0;

	if (!ppol->governor_enabled) {

	if (!ppol->governor_enabled)

		goto exit;



	tunables = ppol->policy->governor_data;

	if (!tunables->use_sched_load || !tunables->use_migration_notif)

		goto exit;



	spin_lock_irqsave(&ppol->target_freq_lock, flags);

	ppol->notif_pending = true;

	ppol->notif_cpu = cpu;

	spin_unlock_irqrestore(&ppol->target_freq_lock, flags);



	if (!hrtimer_is_queued(&ppol->notif_timer))

		hrtimer_start(&ppol->notif_timer, ms_to_ktime(1),

			      HRTIMER_MODE_REL);

exit:

	up_read(&ppol->enable_sem);

	return 0;

}

	tunables = ppol->policy->governor_data;

	if (!tunables->use_sched_load || !tunables->use_migration_notif) {



static enum hrtimer_restart cpufreq_interactive_hrtimer(struct hrtimer *timer)

{

	struct cpufreq_interactive_policyinfo *ppol = container_of(timer,

			struct cpufreq_interactive_policyinfo, notif_timer);

	int cpu;



	if (!down_read_trylock(&ppol->enable_sem))

		return 0;

	if (!ppol->governor_enabled) {

		up_read(&ppol->enable_sem);

		return 0;

	}



	cpu = ppol->notif_cpu;

	trace_cpufreq_interactive_load_change(cpu);

	spin_lock_irqsave(&ppol->target_freq_lock, flags);

	ppol->notif_pending = true;

	spin_unlock_irqrestore(&ppol->target_freq_lock, flags);

	del_timer(&ppol->policy_timer);

	del_timer(&ppol->policy_slack_timer);

	cpufreq_interactive_timer(cpu);



	up_read(&ppol->enable_sem);

	return 0;

	return HRTIMER_NORESTART;

}



static struct notifier_block load_notifier_block = {
@@ -1566,6 +1587,8 @@ static struct cpufreq_interactive_policyinfo *get_policyinfo( 
	ppol->policy_timer.function = cpufreq_interactive_timer;

	init_timer(&ppol->policy_slack_timer);

	ppol->policy_slack_timer.function = cpufreq_interactive_nop_timer;

	hrtimer_init(&ppol->notif_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);

	ppol->notif_timer.function = cpufreq_interactive_hrtimer;

	spin_lock_init(&ppol->load_lock);

	spin_lock_init(&ppol->target_freq_lock);

	init_rwsem(&ppol->enable_sem);